This invention relates to semiconductor devices formed in large numbers on a single semiconductor wafer and then diced into individual devices. The devices of the present invention are designed so as to increase the yield from a single wafer.
Power semiconductor elements with a current capacity of from several to ten-odd amperes widely employed at present have a mesa type glass passivation structure. They are advantageous in that manufacturing costs are low while the surface condition is well stabilized and the electric characteristics are excellent. Therefore those elements can be encapsuled in plastic coverings. However, power semiconductor elements of the type referred to are disadvantageous in that the semiconductor wafer in which they are formed during their manufacture is easily broken owing to both the grooving of the wafer and residual strains developed in the wafer as a result of a difference in the coefficient of thermal expansion between the particular semiconductive material such as silicon and the associated passivation material such as glass. This has imposed a limitation on the diameter of semiconductor wafers attended by an inability to achieve a further reduction in manufacturing cost.
Accordingly it is an object of the present invention to provide a new and improved semiconductor device formed as one of a plurality of such devices in a single semiconductor wafer at a reduced cost by increasing the yield of the devices from the wafer without causing a deterioration of electric characteristics thereof.